U.S. officials worry about homegrown terrorism plots

[efoods]Top Obama administration officials on Wednesday said recent arrests in alleged bombing plots highlight the challenges they face combating “self-radicalized, homegrown extremists” as well as foreigners in the United States determined to carry out attacks.

Najibullah Zazi, an Afghan-born man living legally in Colorado, was charged last week with planning a bombing attack in the United States, and a Jordanian man who overstayed a visa permit was accused of trying to bomb a Dallas skyscraper.

Those and other recent arrests have prompted alerts to law enforcement agencies to step up vigilance on transit systems, in luxury hotels and at sports stadiums.